In this paper, we report deformation behavior during tension followed by
compression loading for Nickel and Nickel-Tungsten alloy (15 at% W)
single crystals using molecular dynamics simulations to investigate the
role of W on the dislocation evolution in Ni-W alloy. The stress-strain
responses of single crystals under uniaxial tension followed by
compression loading after different pre-strains (i.e. 0.10 and 0.20 true
strains for pure Ni; 0.10 and 0.24 true strains for Ni-15 at% W alloy)
are simulated at strain rate of 10(8) s(-1) and at the temperature of
300 K. Dislocation mobility, dislocation-dislocation interaction and
dislocation-twin interactions are thoroughly investigated to evaluate
their influence on deformation behaviour during reverse loading. Slip
dominated deformation mechanism prevails during forward loading but both
twin and slip are found to be operative during reverse loading for Ni
single crystal. It is observed that the dominant deformation mechanism
is twin for both forward and reverse loading in case of Ni-15 at% W
alloy single crystal.